Advertisements
Advertisements
प्रश्न
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
विकल्प
reduction
corrosion
oxidation
decomposition
Advertisements
उत्तर
When the positive charge on an ion increases or the negative charge on them decreases it is called as oxidation.
APPEARS IN
संबंधित प्रश्न
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Define corrosion.
What are anti-oxidants?
When SO2 gas is passed through saturated solution of H2S, the following reaction occurs:
SO2 + 2H2S → 2H2O + 3S
In this reaction, which substance is oxidised and which one is reduced?
Explain the following in terms of gain or loss of oxygen with one example:
Oxidation
When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
In the reaction represented by the following equation:
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
- name the substance oxidised
- name the substance reduced
- name the oxidising agent
- name the reducing agent
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Define an oxidation reaction.
Explain the following in term Reduction of gain or loss of oxygen with two example.
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
Identify from the reaction the reactants that undergo oxidation and reduction.
\[\ce{NiO + H2 -> Ni + H2O}\]
Explain the following in term of gain or loss of oxygen with two examples.
Oxidation
Explain the following in term of gain or loss of oxygen with two examples.
Reduction
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
PbO + CO → Pb + CO2
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Cl2 + H2S → 2HCl + S
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Cu2+ → Cu + Zn 2+
Write the equation in the ionic form
CuSO4(aq) + Fe(s)→ FeSO4(aq) + Cu(s)
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
State the condition and give balanced equation for the conversion of coke to water gas.
Explain the term oxidation in term of addition and removal of oxygen/hydrogen with a suitable example.
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
Give two tests for a reducing agent.
Write chemical formula for rust.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
Identify the following reactions as oxidation or reduction
- Na → Na+ + e
- Fe3+ + 2 e- → Fe+
Rusting of iron involves a chemical reaction which is a combination of:
In the reaction of iron with copper sulphate solution:
CuSO4 + Fe → Cu + FeSO4
Which option in the given table correctly represents the substance oxidized and the reducing agent?
| OPTION | Substance Oxidized | Reducing Agent |
| A | Fe | Fe |
| B | Fe | FeSO4 |
| C | Cu | Fe |
| D | CuSO4 | Fe |
Identify the reducing agent in the following reactions
`4"NH"_3 + 5"O"_2 -> 4"NO" + 6"H"_2"O"`
Identify the reducing agent in the following reactions
`2"H"_2 + "O"_2 -> 2"H"_2"O"`
Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grapes ferment? Is it a chemical or a physical change?
Which among the following are physical or chemical change?
Evaporation of petrol
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
The temperature of the reaction mixture rises when aluminium (Al) is added.
Explain this observation giving suitable reason.
Why do we store silver chloride in a dark coloured bottle?
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained :
- Write a balanced chemical equation for the reaction involved.
- What other name can be given to this precipitation reaction?
- On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
Write a short note on oxidizing and reducing agents.
Oxidizing agents are otherwise called ______.
The tarnishing of metals is an example of ______ reaction.
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
What are redox reactions? Give examples.
Define oxidation number.
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
Find the oxidation number of the element in the following compound.
N in NH3
Answer the questions based on the equation below:
\[\ce{CH3 - CH2 - OH ->[{[O]}][K2Cr2O7/H2SO4] CH3 - COOH}\]
- What type of reaction is it?
- What is the role of the chemical written on the arrow?
- Give one example of one such type of chemical as in answer (b).
State whether the given chemical reaction is a redox reaction or not. Justify your answer.
\[\ce{MnO_2 + 4HCl->MnCl_2 +2H_2O + Cl_2}\]
Metals are good ______.
